The goal of this 5-year project is to discover large, specific attention-related deficits in patients with schizophrenia (SC) through a program of clinical research guided by basic science models of the role of attention in visual perception and visual working memory (WM). Deficits in attention are fundamental to SC, but the specific cognitive and neural mechanisms underlying the impairments remain largely undetermined. Recent cognitive/neuroscience studies of attention have yielded a broad theoretical framework, accompanied by a rich set of experimental paradigms that can isolate specific attention subsystems. The proposed research will translate these theoretical perspectives and experimental paradigms into a clinical research program that will use both behavioral and event-related potential methods to provide a theoretically motivated and highly specific description of attention deficits in SC. The application focuses on the role of attention in visual perception and WM (Aims 1 & 2) because these have received detailed analyses in the basic science literature and because the clinical literature provides evidence of deficits in these areas. To study the operation of attention in perception, Experiments 1 -5 will assess attentional functioning in the context of sensory detection, visual search, and object segregation. Experiments 6-10 test the hypothesis that patients have specific deficits in using attention to control the encoding of information into WM. The paradigms were chosen for their ability to isolate specific attention-related cognitive processes, yielding large, distinctive patterns of results in normal subjects, thereby increasing the opportunity to observe specific, interpretable deficits in SC. These data will provide new insight into the cognitive/neural systems that are impaired in SC, potentially clarifying the nature of the phenotype, providing new targets for pharmacological treatment, and elucidating the nature of normal attention.